Clinical studies on human umbilical cord blood (CB) transplantation have demonstrated the presence of repopulating stem cells. CB transplantation has many advantages over bone marrow (BM) or mobilized peripheral blood (mPB) transplantation. However, CB transplants contain relatively low cell numbers, which is believed to contribute to delayed engraftment, and may restrict CB transplants to small patients (i.e. less than 20 kg). Ex vivo expansion of CB cells has been proposed to overcome these limitations. Many studies indicate that CB cells are more primitive than BM or mPB cells, and are therefore prime targets for expansion and gene therapy protocols. Aastrom has developed a clinical-scale, automated, GMP cell production system (CPS) which is in clinical trials for BM cell expansion. We propose to evaluate CB stem and progenitor cell expansion in Aastrom's proprietary perfusion culture systems. Proposed phase I studies consist of optimization of culture conditions for CB cell expansion in small-scale systems, followed by a demonstration of feasibility in clinical-scale bioreactors using the optimized conditions. Successful completion of phase I will result in a phase II study for implementation of CB cell expansion in the automated CPS for use in clinical trials. PROPOSED COMMERCIAL APPLICATION: A closed, automated, GMP system for CB cell expansion would be of great value. CB transplants have several advantages over BM or mPB transplants, but are currently limited by the number of cells available. CB cell expansion would alleviate this limitation, thereby facilitating CB transplants for many indications including gene therapy.